Cross-linked polyaniline for production of long lifespan aqueous iron∥organic batteries with electrochromic properties

Authors：Lv, Haiming; Wei, Zhiquan; Han, Cuiping^*; Yang, Xiaolong; Tang, Zijie; Zhang, Yantu; Zhi, Chunyi^*; Li, Hongfei^*

Source：Nature Communications, 2023, 14(1): 3117.

DOI：10.1038/s41467-023-38890-y

• CONDUCTING POLYANILINE
• SPECTROSCOPY
• DEGRADATION
• SURFACE
• LAYER
• XPS

Aqueous iron batteries are appealing candidates for large-scale energy storage due to their safety and low-cost aspects. However, the development of aqueous Fe batteries is hindered by their inadequate long-term cycling stability. Here, we propose the synthesis and application as positive electrode active material of cross-linked polyaniline (C-PANI). We use melamine as the crosslinker to improve the electronical conductivity and electrochemical stability of the C-PANI. Indeed, when the C-PANI is tested in combination with a Fe metal negative electrode and 1M iron trifluoromethanesulfonate (Fe(TOF)(2)) electrolyte solution, the coin cell can deliver a specific capacity of about 110 mAh g(-1) and an average discharge voltage of 0.55 V after 39,000 cycles at 25 A g(-1) with a test temperature of 28 degrees C +/- 1 degrees C. Furthermore, mechanistic studies suggest that Fe2+ ions are bonded to TOF- anions to form positively charged complexes Fe(TOF)(+), which are stored with protons in the C-PANI electrode structures. Finally, we also demonstrate the use of C-PANI in combination with a polymeric hydrogel electrolyte to produce a flexible reflective electrochromic lab-scale iron battery prototype.

• Institution
  中国科学院